First principles studies of band offsets at heterojunctions and of surface reconstruction using Gaussian dual-space density functional theory

The use of localized Gaussian basis functions for large scale first principles density functional calculations with periodic boundary conditions (PBC) in 2 dimensions and 3 dimensions has been made possible by using a dual space approach. This new method is applied to the study of electronic properties of II–VI (II=Zn, Cd, Hg; VI=S, Se, Te, Po) and III–V (III=Al, Ga; V=As, N) semiconductors. Valence band offsets of heterojunctions are calculated including both bulk contributions and interfacial contributions. The results agree very well with available experimental data. The p(2 × 1) cation terminated surface reconstructions of CdTe and HgTe (100) are calculated using the local density approximation (LDA) with two-dimensional PBC and also using the ab initio Hartree–Fock (HF) method with a finite cluster. The LDA and HF results do not agree very well

First principles studies of band offsets at heterojunctions and of surface reconstruction using Gaussian dual-space density functional theory

The use of localized Gaussian basis functions for large scale first principles density functional calculations with periodic boundary conditions ͑PBC͒ in 2 dimensions and 3 dimensions has been made possible by using a dual space approach. This new method is applied to the study of electronic properties of II-VI ͑IIϭZn, Cd, Hg; VIϭS, Se, Te, Po͒ and III-V ͑IIIϭAl, Ga; VϭAs, N͒ semiconductors. Valence band offsets of heterojunctions are calculated including both bulk contributions and interfacial contributions. The results agree very well with available experimental data. The p͑2ϫ1͒ cation terminated surface reconstructions of CdTe and HgTe ͑100͒ are calculated using the local density approximation ͑LDA͒ with two-dimensional PBC and also using the ab initio Hartree-Fock ͑HF͒ method with a finite cluster. The LDA and HF results do not agree very well

Island Dynamics and the Level Set Method for Epitaxial Growth

We adapt the level set method to simulate the growth of thin films described by the motion of island boundaries. This island dynamics model involves a continuum in the lateral directions, but retains Research supported in part by NSF and DARPA through grant NSF-DMS9615854 as part of the Virtual Integrated Prototyping (VIP) Initiative. y Mathematics Department, UCLA. Email: [email protected]. z HRL Laboratories. Email: [email protected]. x Mathematics Department, UCLA. Email: [email protected]. -- Mathematics Department, UCLA. Email: [email protected]. k HRL Laboratories and Mathematics Department, UCLA. Email: [email protected]. Physics Department, Imperial College. Email: [email protected]. yy HRL Laboratories. Email: [email protected]. atomic scale discreteness in the growth direction. Several choices for the island boundary velocity are discussed, and computations of the island dynamics model using the level set method are presented. KEYWORDS: epitaxy, leve..